How do I fade a procedural clouds on the edges of a bounding box?
Basically you can try it with this setup and tweak a bit the values to your needs:
What it does: a spherical gradient texture influences (multiplies) the value of the clouds so that they &quot;disappear&quot; to the edges of the sphere.
Of course you could do something similar with a box if you prefer box-like-clouds.

result: